Crude Oil Blends Research Articles

Improving Crude Oil Storage Tank Heating and Blending Using Multiple Hot Jet Sprays: An Experimental and Numerical Study

Improving Crude Oil Storage Tank Heating and Blending Using Multiple Hot Jet Sprays: An Experimental and Numerical Study

Hydro-co-processing Jatropha oil and crude oil blend with Ni-Mo-supported Al2O3 catalyst to produce hybrid fuels: the effect of catalyst particle size

Hydro-co-processing Jatropha oil and crude oil blend with Ni-Mo-supported Al2O3 catalyst to produce hybrid fuels: the effect of catalyst particle size

A method for predicting tank bottom sludge formation during crude oil storage

The laboratory method for predicting the amount and composition of sludge accumulated during crude oil storage on the bottom of a high capacity storage tank has been developed and tested. The laboratory model of the storage tank on a scale of 1:20 was designed with the assumption of a 20-fold acceleration of the process of sedimentation of wax particles and, thus, the formation of a bottom sludge. The results of the model and industrial scale (in the high capacity tank) storage of a Russian export blend crude oil were compared and excellent agreement was found. The developed method was used to evaluate an Iran Light crude oil and a blend of crude oils, Azeri Light, and CPC. The diametrically different behaviour of the compared crude oils during their model storage was ascribed to the different paraffinic particles size distributions and rheologic properties. The correlation between the composition of the crude oil and its tendency to form a sludge at the bottom of the storage tank was not found.

On establishing a benchmark crude in the Russian Arctic

The article analyzes the prospects for establishing Russian benchmark crude based on the arctic blend “Vostok Oil” with a price basis in Murmansk. The relevance of the study is conditioned by the importance of the pricing system’s transparency for maintaining a stable macroeconomic situation in Russia, with a leading role of Artic oil and gas potential for Russian economic development. The authors highlight the main signs of the modern pricing system’s crisis and note that amid the imposed anti-Russian sanctions pricing at European spot hubs can no longer reflect the real situation in the Russian oil market. As a result, there is a need to create a national pricing system by developing the Russian benchmark based on the crude oil blend with the dominance of “black gold” from the Vostok Oil project, which has a high-expected liquidity. The port of Murmansk, being distinguished by unique technical characteristics and access to the logistics potential of the Northern Sea Route, is proposed as a price basis and a price hub. The article presents a four-stage model for launching a corresponding futures contract on SPIMEX, which will help improve the exchange trading system for energy resources in Russia and increase the popularity of the Russian Arctic benchmark crude in the global oil market. In conclusion, the authors underline that the creation of a new benchmark and the launch of futures will ensure stability, transparency and independence of Russian oil exports.

Integrated optimization of crude oil procurement planning and blending scheduling for property stabilization

Crude oil procurement and blending are key processes in refinery production. When solving the integrated optimization problem of simple oil procurement and blending, the following issues are mainly considered: how to establish an integrated optimization model of crude oil procurement and blending process under different time scales to minimize the cost of procurement under the premise of ensuring the stability of the properties of blended crude oil. The paper proposes an integrated optimization model, takes cost minimization as the model's objective function, and provides stability through the yield and property constraints of blended crude oil. Then, the paper describes the procurement process by an event-based representation and the blending process by a continuous event representation and proposes a hybrid event-time-based representation to describe the model. Finally, this paper verifies the model's effectiveness in solving real production problems through case simulations.

Optimisation of Vacuum Distillation Units in Oil Refineries Using Surrogate Models

To ensure the optimum performance of downstream processes in a petrochemical refinery, the operation of a vacuum distillation unit (VDU) is critical. It needs to satisfy the yield and quality requirements of the downstream process. Otherwise, it will result in a loss of profitability in the refinery. Hence, it is important to optimise the operation of the VDU to ensure optimum performance. Traditionally, VDU is operated within the design envelope, and its operation condition is fine-tuned based on the operator’s experience. However, such action does not guarantee the optimum performance of the entire refinery as it only considers the operation of VDU without understanding the effects towards downstream processes. Therefore, this work presents a framework to optimise VDU operations with consideration of the downstream processes. The framework consists of process simulation, surrogate modelling, and multi-objective optimisation. The developed framework aims to determine trade-offs between high vacuum gas oil (HVGO) yield and total annualised cost (TAC) of a refinery that considers the needs of downstream operations. In this work, crude oil blending ratio, furnace outlet temperature, flash zone temperature, column top pressure, column bottom pressure, stripping steam flowrate, HVGO pump-around flowrate, and light vacuum gas oil (LVGO) pump-around flowrate of the VDU are to be optimised. Based on the optimised result, the heavy-light crude blend achieves higher HVGO yield and lower TAC, and the optimised results were validated with the simulation results via Aspen HYSYS. The proposed methodology was proven to have accurate estimations of the VDU operation in the process simulation environment. Moreover, the optimised results can provide insight into the optimal process conditions of VDU for the refiners. With this insight, effective operating strategies can be developed to overcome the limitations present in real VDU operations.

P38- and ERK-MAPK Signalling Modulate Developmental Neurotoxicity of Nickel and Vanadium in the Caenorhabditis elegans Model

Nickel (Ni) and vanadium (V) are characteristic heavy metal constituents of many crude oil blends in Sub-Saharan Africa, and we have previously demonstrated their neurotoxic impact. However, molecular mechanisms driving Ni and V neurotoxicity are still being elucidated. The p38- and ERKs-MAPK pathways, which are mostly known for their involvement in human immune and inflammatory signalling, have been shown to influence an array of neurodevelopmental processes. In the present study, we attempt to elucidate the role of p38- and ERK-MAPK in neurotoxicity after early life exposures to Ni and V using the Caenorhabditis elegans model. Synchronized larvae stage-1 (L1) worms were treated with varying concentrations of Ni and V singly or in combination for 1 h. Our results show Ni induces lethality in C. elegans even at very low concentrations, while much higher V concentrations are required to induce lethality. Furthermore, we identified that loss-of-function of pmk-1 and pmk-3, which are both homologous to human p38-α (MAPK14), is differentially affected by Ni and V exposures. Also, all exposure scenarios triggered significant developmental delays in both wild-type and mutant strains. We also see increased mitochondrial-derived reactive oxygen species following Ni and V exposures in wild-type worms with differential responses in the mutant strains. Additionally, we observed alterations in dopamine and serotonin levels after metal exposures, particularly in the pmk-1 strain. In conclusion, both Ni and V induce lethality, developmental delays, and mitochondrial-derived ROS in worms, with V requiring a much higher concentration. Further, the results suggest the p38- and ERK-MAPK signalling pathways may modulate Ni and V neurodevelopmental toxicity, potentially affecting mitochondrial health, metal bioavailability, and neurotransmitter levels.

Environmental impact of fouling for crude oil flow in preheat pipes according to oil blends

Crude oil fouling is a complex process caused by multiple mechanisms. This study examined fouling's environmental impact on a distillation unit's heating tubes and heat exchangers, proposing optimal pollution levels to reduce emissions and achieve sustainability goals. The study evaluated five crude oil blends in terms of API, sulphur, salt content, and other physical properties. Contaminated water was analyzed through biological and chemical means, while CO2, NOx, and SOx emissions were calculated from actual fuel and power consumption. Solid and sludge sediments were observed throughout all plate heat exchangers, consisting primarily of iron hydroxides and manganese oxides. Rationalizing energy use reduced the burden on the environment and fuel consumption by 7 %, with a 2 % reduction in energy needed to refine crude oil feeding units when fouling is removed after maintenance. By optimizing pollution levels and reducing energy consumption, the environmental impact of fouling can be mitigated.

Experimental Evaluation of the Deposition Dynamics of Different Petroleum Blends in a Benchtop Heat Exchanger Test Instrument

The article delves into the intricate phenomenon of deposition in heat exchangers and how a piece of equipment known as the benchtop heat exchanger test instrument (BHETI) has been developed to expedite the examination of this phenomenon. The BHETI subjects samples to substantial stress, facilitating the assessment of an oil’s tendency to generate deposits. Tests were conducted on two crude oil blends referred to as blend A and blend B using a BHETI unit. This equipment permits testing under various controlled conditions, including temperature, pressure, and volumetric flow rate. The results indicated that blend A exhibited a higher susceptibility to deposition compared to blend B due to its elevated concentration of light hydrocarbons. The wall temperature exerted a significant influence on the deposition rate, with higher temperatures leading to elevated deposition rates. Conversely, lower oil flow rates resulted in increased deposition rates. Furthermore, extended-term tests unveiled fluctuations in deposition rates over time when blending the two oil samples, suggesting intermittent fouling processes, possibly attributable to thermodynamic imbalances induced by mixing, rendering the oil’s asphaltenes less stable. The outcomes were subjected to analysis employing the Colloidal Instability Index (CII), which indicated that the majority of samples exhibited values exceeding 0.9, signifying asphaltene instability. Additionally, the examination of saturated, aromatic, and NSO (nitrogen, sulfur, oxygen) fractions revealed decreased saturation and increased aromatics after the deposition tests.

Relative compatibility index for evaluation of the compatibility of crude oil blends

A new relative compatibility index is proposed to evaluate the compatibility of blends of crude oils. The approach considers the calculation of solvent power of individual crude oil and their blends, the critical solvent power for blends of crude oils with required amount of n-heptane when precipitation of asphaltenes begins, and a graphical comparison of both parameters (solvent power and critical solvent power) to determine the maximum proportion of crude oils in the blend to avoid incompatibility problems. The proposed method requires experimental data that are commonly available, such as specific gravity, TBP (True Boiling Point) distillation, and S-value (fuels stability determination according ASTM D 7157). Eight crude oils with a wide range of API (American Petroleum Institute) gravity (10–52°) were used to validate the method. It was demonstrated that the proposed approach accurately predicts the compatibility of blends of crude oils, and that relative compatibility index is an effective parameter to define appropriate amounts of crude oils to avoid asphaltenes precipitation during blending.

Do the True Boiling-Point Distillation Yields of Crude Oil Blends Obey the Additive Blending Rule?

Twelve crude oil blends prepared from seven individual crude oils and an imported atmospheric residue were characterized through a true boiling point (TBP) distillation analysis and their density. When comparing the measured TBP fraction yields with those estimated through the application of the additive blending rule, it was found that, for four crude oil blends, the additive blending rule was valid, while for the remaining eight crude oil blends, deviations of the measured TBP yields from the estimated ones were bigger than the TBP analysis’s repeatability limits. By the use of intercriteria analysis evaluation of the data for the deviation of the TBP yields from the additive blending rule and the molar excess volume of the crude oil blends, statistically meaningful relations between the delta TBP yields of light and heavy naphtha, as well as vacuum residue with the molar excess volume, were found. The higher the magnitude of the crude oil blend’s molar excess volume, the bigger the deviations of the TBP yields of naphtha and vacuum residue are. The bigger the deviation of the crude oil blend’s behavior from that of the regular solution, as quantified by the molar excess volume, the bigger the deviations of the TBP yields of naphtha and vacuum residue are.

Optimum Blending of Crude Oils Using Linear Programming

Optimum Blending of Crude Oils Using Linear Programming

Simplified regular solution model for asphaltenes precipitation in crude oil blends

The regular solution model is used with Hankinson-Brobst-Thomson (HBT) molar volume correlation for saturates, aromatics, resins and asphaltenes (SARA) fractions for pure crude oils and blends to predict the precipitation of asphaltenes. The parameters of the HBT correlation were tuned with experimental data for SARA fractions densities. At the same temperature and pressure conditions, the precipitation of asphaltenes is greatly influenced by the presence of other compounds. SARA fractions were obtained according with ASTM D2007 using n-heptane as precipitant solvent. The use of average properties for saturates, aromatics and resins and the assumptions made in the model could reproduce precipitation curves for all study cases. Calculations of asphaltene precipitation prediction for pure oils showed an average absolute deviation between 0.12 and 0.69% for oil of Gulf of Mexico and Cold Lake oil, respectively. For blends it showed values between 0.08 and 0.65% for Cold Lake/Lloydminster-Asphaltene free blend and Cold Lake/Lloydminster-Gulf of Mexico blend respectively. The proposed model maintains its simplicity and can predict the asphaltene precipitation accurately.

Determination of rheological properties of crude oil blends

The article presents an overview of widely applicable methods of calculation of viscosity of liquid mixtures, as well as rheology characterisation of crude oil. It is focused on the evaluation of rheological properties, particularly in order to assess the flow conditions in pipelines at different temperatures and flow rates, especially in the case of waxy crude oils. A specific calculation procedure was proposed and described, suitable for practical purposes, i.e. field implementation in the form of a spreadsheet calculator. Using this method, it is possible to calculate the rheological properties of a mixture of known components at a given temperature over a range of shear gradients corresponding to a specified range of flow rates in a circular pipeline of specified diameter. The proposed calculation method was verified on the properties of specific types of oils and their mixtures.

Effect of ultrasonic homogenization on crude oil-water emulsion stability

This research aims to evaluate the effect of ultrasonic processing parameters (power and sonication time), emulsion characteristics (water salinity and pH) and their interaction on oil-in-water emulsion stability for Cold Lake Blend (CLB) crude oil. Response surface methodology was used to design experimental runs, in which the parameters were investigated at five levels. Emulsion stability was evaluated by measuring creaming index, emulsion turbidity and microscopic image analysis. The effect of crude oil condition (fresh and weathered) on the emulsion stability was also investigated at the optimum sonication parameters and emulsion characteristics. The optimum condition was found at a power level of 76–80 W, sonication time of 16 mins, water salinity of 15 g/L NaCl, and pH of 8.3. Increasing sonication time beyond the optimum value had adverse effect on the emulsion stability. High water salinity (> 20 g/L NaCl) and pH (> 9) decreased the emulsion stability. These adverse effects intensified at higher power levels (> 80–87 W) and longer sonication times (> 16 mins). Interaction of parameters showed that the required energy to generate stable emulsion was within 60 − 70 kJ. Emulsion with fresh crude oil was more stable than those generated with the weathered oil.

Effect of Aging on Deposit Characteristics Obtained by Crude Oil Blending

In this study, the characteristics of the precipitated material product of the blending of two crude oils are analyzed as a function of aging time. In general, the deposits are enriched in asphaltenes and waxes in comparison to the parent crude oils. They also contain a significant amount of maltenes. The results also indicate that the amount and composition of the deposit change as the deposit ages. A decrease in the amount of the deposit is observed at shorter times, but later, the deposit amount increases until it reaches a plateau at longer times. During aging, the deposit becomes more hydrogen deficient and richer in asphaltenes. Waxes in the deposit experience a decrease in concentration at shorter times but an increase at longer times. As the deposit ages, wax distributions shift to longer alkanes. These changes in wax concentrations and distributions are reflected in the wax appearance temperatures as well. Maltenes show the same temporal behavior as waxes as the deposit ages.

Compatibility of Crude Oil Blends─Processing Issues Related to Asphaltene Precipitation, Methods of Instability Prediction─A Review

Processing crude oil of variable composition, especially due to the need to process crude oil blends obtained from various sources, presents a tremendous process challenge. This is mainly due to the destabilization of the colloidal system manifested mostly by the precipitation of the asphaltene fraction. The precipitation of asphaltenes from crude oil is a serious problem during extraction, transport, and processing. In the latter case, engineers and scientists have spent a lot of time determining what mechanisms are conducive to the occurrence of this phenomenon. On the one hand, there was a scientific curiosity about the principles of the nanoworld (nanoscale) of asphaltene molecules that determine their stability, and on the other hand, the willingness of process engineers in refineries to maintain the equipment in the best condition and maximize plant profits. Over the years, many methods have been developed to assess the stability of asphaltenes in crude oils and their blends, starting with methodologies based on the separation of a complex mixture into basic groups of compounds with similar properties (SARA) to sophisticated numerical models on an increasingly better understanding of interactions between molecules under changing conditions. In the former case, the basic instruments available in every laboratory are used whereas in the latter case technically advanced measurement systems capable of reproducing the real conditions of crude oil processing are employed. This paper reviews the methods of determining the stability of crude oils and their blends along with a critical assessment of their effectiveness.

Sudan'daki Bir Rafineride Kullanılan İki Farklı Ham Petrol Türünün Karşılaştırmalı Yaşam Döngüsü Değerlendirmesi

Climate change, caused primarily by fossil fuels used for meeting the increasing energy demand, has become a global concern since the last decade. One of the most important sectors contributing to this demand is transport fuel production. Oil refining is the hotspot for life cycle environmental burdens of all transport fuel types. To respond to this global challenge, all parties need to work in an identical pattern, i.e., socially appropriate, technically feasible, economically sustainable, and environmentally friendly. Specifically, the oil refining industry uses vast amounts of raw materials and creates considerable waste that needs to be processed, mainly at refinery sites. In this study, we compare two different types of crude oil used in Sudan refineries, namely X and Y blend crude oil, in terms of environmental impacts. A detailed Life Cycle Assessment (LCA) defined by the ISO14040/14044 frameworks carried out via SimaPro software v.8.1.1.16. Both midpoint and endpoint approaches were adopted for the ReCiPe impact assessment method. Based on the selected midpoint impact categories, i.e., climate change, ozone depletion, human toxicity, and terrestrial acidification, the X crude oil impact scores were 282.7 kg CO2 eq, 2.45E-06 kg CFC-11 eq, 1.05 kg 1,4-DB eq, and 0.145 kg SO2 eq while the Y crude oil scores were 265.9 kg CO2 eq, 1.58E-06 kg CFC-11 eq, 0.735 kg 1,4-DB eq, and 0.095 kg SO2 eq, respectively. From an endpoint approach considering the representative single scores, overall impacts for the X and Y crude oil created an environmental load output of 13.8 and 12.7 Pt, respectively. As expected, both types of crude oil had a direct impact on the environment, where crude oil Y was found to have 10% less impact than crude oil X.

Modification of the viscosity of extra-heavy crude oil using aqueous extracts of common geranium (Pelargonium hortorum)

The transport of extra-heavy crude oil is a severe problem in the oil industry due to its viscosity, asphaltenes content, and tendency to precipitate. These crude oil's characteristics cause clogging of the pipes and increase production costs. One of the solutions for this problem is the addition of compounds that reduce the viscosity of crude oil and the self-aggregation of asphaltenes. In recent years, new ‘green’ additives have been investigated to replace the use of traditional and more toxic substances, such as toluene. In this study, new common geranium (Pelargonium hortorum) aqueous extracts were synthesized with 1, 5, and 10% (w/v). Its effect on the Mexican extra-heavy (8 °API) crude oil blend was analyzed in a shear rate range of 0.1–60 1/s and constant temperatures of 30, 40, and 50 °C. In addition, its pH, TDS, and EC were measured on days 1 and 15 after synthesis. These synthesized compounds were qualitatively determined using phytochemical analysis. The possible relationship between these compounds and the viscosity modification was analyzed. The results suggest that using these compounds as viscosity modifiers for extra-heavy crude oil could be promising, at higher concentrations in the range of 5–10% and for a temperature range of 40–50 °C, and for lower shear rates. The conclusions suggest further investigation of the common geranium aqueous extracts to understand its effect on crude oil properties.

USE OF GENETIC ALGORITHMS IN CREATING OIL BLENDS REQUIRED FOR REFINERY DISTILLATION PLAN

"In Romania, the oil refineries were designed to process the crude oil extracted from the deposits located in their immediate vicinity (Suplacu de Barcău Refinery, 1 Mai Refinery, Câmpina Refinery, Vega Refinery and Dărmănești Refinery), to process crude oil imported from external oil basins (Onești Refinery, Brazi Refinery, Teleajen Refinery, Midia Refinery and Pitești Refinery) and to process crude oil from the Muntenia and Oltenia oil basins (Brazi Refinery and Pitești refinery). The closing of some refineries after 1990, the reduction of crude oil imports and especially the tightening of the quality conditions of the delivered petroleum products (the need to reduce the sulphur content of petroleum products, the use of bio-fuels) led to the reconsideration of deliveries to the refineries that remained in operation, through the creation of mixtures of crude oils extracted from Romania (for the Brazi Refinery) and the import of crude oil mixtures for the Teleajen and Midia Refineries, which would ensure the new quality conditions of finished petroleum products. The article describe how to create crude oil blends according to refinery requirements, using both classical estimation methods and genetic algorithms to determine the variation in the properties of these blends. "